Clipping plane to neuroglancer in the 3D view to hide a plane

[dxenes1]

No description provided.

[dramsde1]

Things needed for this issue:

1. Creating the plane 3d object

   It's not as simple as importing an obj/fbx file of a plane. Neuroglancer has some built in functionality that controls what.
   points you want in 3d space, what fragment and vertex shaders you can apply and the matrices that are involved in
   transforming all the way from local to canvas space (I based the plane file from the bounding box file).

2. Getting the created plane object to appear and disappear

3. Using the vertex shaders to move the plane object according to a mouse drag or mouse click

4. Hiding data on one side of the plane (the clipping)